Since xsk support in libbpf loads the xdp program interface, make it also responsible for its removal. Store the prog id in xsk_socket_config so when removing the program we are still able to compare the current program id with the id from the attachment time and make a decision onward.
While at it, remove the socket/umem in xdpsock's error path. Signed-off-by: Maciej Fijalkowski <maciej.fijalkow...@intel.com> --- samples/bpf/xdpsock_user.c | 33 ++++++++++----------------------- tools/lib/bpf/xsk.c | 32 ++++++++++++++++++++++++++++++++ tools/lib/bpf/xsk.h | 1 + 3 files changed, 43 insertions(+), 23 deletions(-) diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index e9dceb09b6d1..123862b16dd4 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -68,7 +68,6 @@ static int opt_queue; static int opt_poll; static int opt_interval = 1; static u32 opt_xdp_bind_flags; -static __u32 prog_id; struct xsk_umem_info { struct xsk_ring_prod fq; @@ -170,22 +169,6 @@ static void *poller(void *arg) return NULL; } -static void remove_xdp_program(void) -{ - __u32 curr_prog_id = 0; - - if (bpf_get_link_xdp_id(opt_ifindex, &curr_prog_id, opt_xdp_flags)) { - printf("bpf_get_link_xdp_id failed\n"); - exit(EXIT_FAILURE); - } - if (prog_id == curr_prog_id) - bpf_set_link_xdp_fd(opt_ifindex, -1, opt_xdp_flags); - else if (!curr_prog_id) - printf("couldn't find a prog id on a given interface\n"); - else - printf("program on interface changed, not removing\n"); -} - static void int_exit(int sig) { struct xsk_umem *umem = xsks[0]->umem->umem; @@ -195,7 +178,6 @@ static void int_exit(int sig) dump_stats(); xsk_socket__delete(xsks[0]->xsk); (void)xsk_umem__delete(umem); - remove_xdp_program(); exit(EXIT_SUCCESS); } @@ -206,7 +188,16 @@ static void __exit_with_error(int error, const char *file, const char *func, fprintf(stderr, "%s:%s:%i: errno: %d/\"%s\"\n", file, func, line, error, strerror(error)); dump_stats(); - remove_xdp_program(); + + if (xsks[0]->xsk) + xsk_socket__delete(xsks[0]->xsk); + + if (xsks[0]->umem) { + struct xsk_umem *umem = xsks[0]->umem->umem; + + (void)xsk_umem__delete(umem); + } + exit(EXIT_FAILURE); } @@ -312,10 +303,6 @@ static struct xsk_socket_info *xsk_configure_socket(struct xsk_umem_info *umem) if (ret) exit_with_error(-ret); - ret = bpf_get_link_xdp_id(opt_ifindex, &prog_id, opt_xdp_flags); - if (ret) - exit_with_error(-ret); - return xsk; } diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index 514ab3fb06f4..e28bedb0b078 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -259,6 +259,8 @@ int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size, static int xsk_load_xdp_prog(struct xsk_socket *xsk) { static const int log_buf_size = 16 * 1024; + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); char log_buf[log_buf_size]; int err, prog_fd; @@ -321,6 +323,14 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) return err; } + err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len); + if (err) { + pr_warning("can't get prog info - %s\n", strerror(errno)); + close(prog_fd); + return err; + } + xsk->config.prog_id = info.id; + xsk->prog_fd = prog_fd; return 0; } @@ -483,6 +493,25 @@ static int xsk_set_bpf_maps(struct xsk_socket *xsk) return err; } +static void xsk_remove_xdp_prog(struct xsk_socket *xsk) +{ + __u32 prog_id = xsk->config.prog_id; + __u32 curr_prog_id = 0; + int err; + + err = bpf_get_link_xdp_id(xsk->ifindex, &curr_prog_id, + xsk->config.xdp_flags); + if (err) + return; + + if (prog_id == curr_prog_id) + bpf_set_link_xdp_fd(xsk->ifindex, -1, xsk->config.xdp_flags); + else if (!curr_prog_id) + pr_warning("couldn't find a prog id on a given interface\n"); + else + pr_warning("program on interface changed, not removing\n"); +} + static int xsk_setup_xdp_prog(struct xsk_socket *xsk) { __u32 prog_id = 0; @@ -506,6 +535,7 @@ static int xsk_setup_xdp_prog(struct xsk_socket *xsk) err = xsk_lookup_bpf_maps(xsk); if (err) goto out_load; + xsk->config.prog_id = prog_id; } err = xsk_set_bpf_maps(xsk); @@ -744,6 +774,8 @@ void xsk_socket__delete(struct xsk_socket *xsk) } + xsk_remove_xdp_prog(xsk); + xsk->umem->refcount--; /* Do not close an fd that also has an associated umem connected * to it. diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h index 82ea71a0f3ec..e1b23e9432c9 100644 --- a/tools/lib/bpf/xsk.h +++ b/tools/lib/bpf/xsk.h @@ -186,6 +186,7 @@ struct xsk_socket_config { __u32 tx_size; __u32 libbpf_flags; __u32 xdp_flags; + __u32 prog_id; __u16 bind_flags; }; -- 2.16.1